Enter the estate and who survives. The calculator takes out funeral costs, debts and any bequest, then divides the rest by the shares set in the Qur'an (4:11, 4:12 and 4:176), showing each heir's fraction, amount and the reason for it.
How the shares work
Islamic inheritance gives some relatives a fixed share named in the Qur'an, and gives what is left to the closest male relatives and those who inherit with them. A husband takes half, or a quarter if there are children. Wives share a quarter, or an eighth if there are children. A single daughter with no son takes half; two or more share two thirds. A mother takes a third, or a sixth if there are children or two or more siblings. A father takes a sixth if there are children, and the rest otherwise.
Sons and daughters together
When there is a son, the children inherit what is left after the fixed shares, and a son takes twice a daughter's share. Full brothers and sisters inherit only when there is no son and no father; with daughters but no son or father, full sisters take what is left.
When the shares do not fit exactly
If the fixed shares add up to more than the estate, each is reduced in proportion. This is called awl. If they add up to less and nobody is left to take the remainder, it is returned to the fixed-share heirs in proportion, except the spouse; this is called radd. If only a spouse survives, schools differ on the remainder, and the calculator leaves it unassigned.
Two special cases
When the only heirs are a spouse and both parents, the mother receives a third of what remains after the spouse's share, and the father the rest. These are known as the 'Umariyyatan cases.